Which 'voice' is the Pasuk referring to?
Rashi: It refers to the sound like thunder that the earth emitted as it swallowed them up. 1
Rashbam: It refers to their screams as they went down. 2
Targum Yonasan: It refers to the cries of those who had been swallowed - who proclaimed 3 'Hashem is right, His judgment is Emes, and the words of His servant Moshe are authentic; whereas we are the wicked ones who rebelled against him!' 4
See Sifsei Chachamim. The question remains however, why the Torah writes le'Kolam" (plutal).
Rashbam: As in Yirmiyah, 45:21. See Oznayim la'Torah, who brings further proof from here that this miracle had no bearing to an earthquake.
Who continued to cry out after the earth had closed its mouth. See Oznayim la'Torah DH 'Nasu le'Kolam' #2/
Michtav me'Eliyahu (1, p.299): Rabah bar bar Chanah heard them announcing this. Why were they still saying it one thousand five hundred years after they were swallowed? Did they not yet learn this?! Indeed, no - they are not saying it from the depth of their hearts. The way a person goes in this world, so he is in the world to come!
